Switching system



Se t, 27, 1949.

v D! L. HERR SWITCHINQ- SYSTEM 7 Sheets-Sheet Filed Sept. 17, 1 947 79flmzaldL-Herr,

ATTOHW Sept. 27, 1949. D. L. HERE! 2,483,231

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Arrmrm Sept. 27, 1949. D. L. HERR 2,483,281

SWITCHING SYSTEM Filed Sept. 17, 1947 7 Sheets-Sheet 4 Fig.5

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HTTQHAHZ'Y Sept. 27, 1949. o. 1.. HERR SWITCHING SYSTEM 7 Sheets-Sheet 5\T s. INVENTOR.

Filed Sept. 17, 1 947 P 1949. o. L. HERR 2,483,281

SWITCHING SYSTEI Filed Sept. 17, 1947 Sheets-Sheet 6 RELAYS A5 TO H3SUPPLY INVENTOR DonaldLHarz;

BTTQRATY Sept. 27, 1949. D. L. HERR SWITCHING SYSTEM 7 Sheets-Sheet '1Filed Sept. 17, 1947 INVENTOR. flazzald L. Hen;

Patented Sept. 27, 1949 SWITCHING SYSTEM Donald L. Herr, Brooklyn, N.Y., assignor to Control Instrument Company, Inc., Brooklyn, N. Y., acorporation of New York Application September 17, 1947, Serial No.774,613

4 Claims.

This invention relates to improvements in switching systems and hasparticular reference to a system for automatically controlling theselective interconnection between various instrumentalities.

It has been the practice in difierent types of switching systems, toutilize a mutiplicity of instruments, some of which may control theoperation of others, and to provide for manually establishinginterconnection between said instrumentalities whereby any one or moreof them may be operatively connected to any of the others.

The present invention proposes an improved switching system whereindiversified interconnection between instrumentalities is accomplished bythe arbitrary selection of any one of a plurality of control elementseach having different media for identifying one of a plurality ofcombinations of instrument interconnections, and by causing the selectedelement to automatically control the establishment of the desiredconnection.

The inventive idea involved is capable of receiving a variety ofexpressions, one of which, for purposes of illustration, is shown in theaccompanying drawings; but it is to be expressely understood that saiddrawings are employed merely to facilitate the description of theinvention as a whole and not to define the limits thereof, referencebeing had to the appended claims for this purpose.

In the drawings:

Fig. 1 is a schematic view illustrating a switching system embodying thefeatures of the present invention;

Fig. 2 is a top plan view of a selector mechanism employed in connectionwith the present system;

Fig. 3 is a fragmentary end elevation of said mechanism showing theparts at an intermediate stage of the operation thereof;

Fig. 4 is a transverse section on the line 4-4 of Fig. 2 with parts inthe position shown in Fig. 3;

Fig. 5 is an enlarged fragmentary sectional view, somewhat similar toFig. 4, illustrating the mechanism in position after a selectingoperation has been completed;

Fig. 6 is a section on the line 68 of Fig. 2;

Fig. '7 is a section on the line of Fig. 2;

Fig. 8 is an elevation, partly in section, showing a portion of thedrive mechanism for the selector;

Fig. 9 is a side elevation, partly in section, of the selector mechanismshowing the banks of switch contacts and the means for controlling thesame;

Figs. 10, 11 and 12, when taken together with Fig. 11 arranged belowFig. and Fig. 12 to the right of Fig. 11, show diagrammatically thecircuits involved in the system; and

Fig. 13 is a diagrammatic view of a selector device employed to transmitsignals to said selector mechanism.

The invention is herein described in its adaptation to a switchingsystem in which one of its functions is to establish variouscombinations of generator-load interconnections, but it will be apparentas this description progresses that the invention, without departingfrom the spirit or scope thereof, is applicable to other switchingsystems, for example, wherein synchro transmitters and receivers may becoupled together or directors of a gunnery fire control system may beselectively connected to various gun mounts; and, in fact, to any systemin which interconnection may be established between variousinstrumentalities, whatever their nature, through different selectablechannels.

Referring to Fig. 1, there is conventionally indicated a switchboard [5wherein is contained a plurality of switching devices which may be motordriven multi-position switches of a type exemplified in the co-pendingapplication of Edward Lohse, Serial No. 773,834, filed September 13,1947, and which operate through their various positions, toestablishdifierent channels of communication. Thus, in the exampleshown, any number of instruments 16a I61) and H50, which may begenerators for example, are connected to the switchboard through cables[1, and a like or different number of other instruments l8a, [8b andI80, such as loads, are also joined to said switchboard by cables It] sothat through the proper setting of the switches above referred to, it ispossible to selectively interconnect any combination of saidinstrumentalities.

In conformity with the present invention, it is proposed to establishsaid interconnections by controlling, from a point or points remote fromthe switchboard, the automatic selection, from a plurality of controlelements, of one element which has identifying media thereon individualto the desired instrument combination, and to utilize the selection ofsaid control element to activate the switch or switches at the board l5necessary to complete the interconnection between the instruments ofsaid combination. The number of control elements, and therefore thenumber of interconnections, is arbitrary and depends upon therequirements of the system in which they are employed. These elementsare located in a control unit 20 which also contains the selectormechanism illustrated in Figs. 2 to 9 and which operates to select acontrol element required to establish the desired combination ofinstruments [6, l8. The establishment of this interconnection iseffected through the medium of a transmission unit 2| joined to the unit20 by the cable 22 containing the line voltage conductors. In said unit2! are a number of groups of motorized rotary relays (see Fig. 11) equalto the number of groups of switch contacts contained in the banks ofswitches illustrated in Fig. 9, with each contact being individual to arelay. Again, the number of groups of switch contacts and relays may bevaried in, accordance with the requirements of the system to which theinvention is to be adapted. When any combination of said relays,depending upon the identifying media on one of the aforesaid controlelements, is energized by the selection of said element, said relayswill, over the transmission lines contained in the cable 23, activatethe motor driven multi-position switches at the board |5 required toestablish the desired instrument interconnection. Upon selection of anycontrol element, a visual signal individual thereto and contained in theunit 24, will be energized and remain thusly until another selection ofa control element is made.

In some systems, it may be desirable to effect the selection of acontrol element at the unit 29 from any one of a plurality of remotelyconnected substations, 251, 252, etc. through a station selector switch26 which may be manually controlled and which, together with the units20, 2| and 24, may be located at a main station designated as 21. Acontrol element selector 28 having a plug 29 is adapted to be connectedto an outlet at any one of said substations and, by telephonic or othermeans (not shown), information may be obtained from an attendant at themain station identifying the particular control element then in effect.Should a change in the set-up of the instruments l6 and I8 be desired,the attendant will cause the station selector 26 to be operated toconnect a substation with the selector mechanism at the unit 20. Theoperator of the selector 28 at said substation will then press a key(see Fig. 13) individual to the control element required to establishsuch change, and this action will produce a signaling impulse over theconductor 29 which will initiate the operation of said selectormechanism.

Before proceeding to a detailed description of the circuit arrangementof the system in its entirety, the construction and operation of thecontrol element selector mechanism shown in Figs. 2 to 9 and located atthe unit 20 will first be set forth.

This mechanism comprises a supporting base 3!] upon which are mountedtwo banks of switches generally indicated at 3| and 32. Each bankcomprises any number of normally open switch contacts which may berequired by the system and it is the closing of any of these contactswhich energize a, motor driven relay contained in the transmission unit2| and shown diagrammatically in Fig. 11. Two perpendicular frames aresecured to the base 3|! adjacent the ends of said banks of switches andhave mounted thereon a stationary guide plate 36 which supports ahorizontal frame 31. Outwardly of the end frames 35, the base 30 alsosupports two pairs of standards 38 utilized to guide a verticallymovable press member or plate 39 which, as will presently appear,controls the closing of selected sets of contacts in the banks 3|, 32 inits downward movement and which is raised during an interval of theoperation of the selector mechanism when any one of a plurality ofstacked control elements 40 is being selected, there being six of suchelements shown herein, one for an off position and the remaining fivefor making various instrument interconnections. Each element is in theform of a rectangular plate and is provided thereunder with a supportingholder 4| which is adapted to be reciprocated in a transverse directionto adjust its plate 40 from inoperative to operative position when it isselected for the control of contacts 3|, 32 individual thereto. In orderthat each plate will be shifted with its holder, the former is providedat each end with a longitudinal slot 42 (see Figs. 2 and '7) whichreceives a stud 43 carried by the holder. Said holders have strucktherefrom along adjacent longitudinal edges the angular flanges 44 (Fig.6) all of difierent lengths and, when the holders are stacked, theflanges of increasing length toward the top of the stack will projectdownwardly through the lower holders and will be longitudinally spacedfor connection to a mechanism later to be described which willsuccessively reciprocate the holders during the selection of one of theelements 40. To support the elements 40 and their holders in stackedposition and for individual selection, the same are placed upon a baseplate 45 mounted on the frame 31 above the plate 36 and, in order toprevent endwise shifting of the elements 40, 4|, vertical guide rollers46 (Fig. 9) are carried by the frame 31 at each end thereof for contactwith the end or transverse edges of said elements. After being sostacked, a removable weighted member 41, having end flanges 48 whichengage with the ends of the frame 31, is placed in position over thestack and said member and flanges are provided with rollers 49 whichthen engage the top element 40 at its center end ends, whereby thestacked elements will be maintained in their respective horizontalplanes at all times during the operation of the selector mechanism. Bymeans of such construction, it will be apparent that the holders andtheir plates may be removed and other plates substituted whenever it isdesired to obtain instrument interconnections other than those capableof being established by the removed plates.

Each element or plate 40 is individual to one combination of instrumentinterconnection I6, l8 and has means thereon for identifying the same,so that when said plate is selected by a shifting of its associatedholder to an operative position, the plate will cause, as will presentlyappear, the closing of those switch contacts 3|, 32 necessary toenergize the relays in the unit 2| which will position the switches onthe switchboard |5 that establish the desired interconnection ofinstruments. The identifying media on each plate which control theoperation of switches 3|, 32 comprises long and short slots 50 and 5|respectively, and the holder 4| for said plate is provided only withlong slots 52 that are aligned with said slots 50, 5| so that when allthe plates and holders are stacked the slots therein are in verticalalignment. The slots 5|], 5| of each plate are arranged in two rows, asshown in the top plate of Fig. 2, and the number of slots is equal tothe number of switch contacts in the banks 3|, 32 which are, in turn,equal to the number of relays contained in the transmission unit 2|.Also, there is provided a switch operating or transfer device, generallyindicated at 53, for each group of vertically aligned slots in thevarious plates and their holders, and said device is individual to oneof the switch contacts in the banks 3| or 32, and is designed to closesaid contacts after the device is adjusted to its operative position bythe appearance of short slots 5| in a plate 40 when the latter isshifted by its holder 4|. Each device 53 comprises the upper and lowerpin sections 54 and 55 the former of which extends upwardly through theplates 36 and 45 and the associated vertically aligned slots 50, 5| and52 in the elements 40 and their holders 4|. The sections 54, 55 arepivotally and slidably interconnected by a vertical slot 56 in the lowerend of the section 54 which receives a pin 51 on the upper end of thesection 55. The sections 54 of the various devices 53 are supported forsliding movement by flanges 58 engaging the plates 36 and 45 and, byreason of the transverse slots 59 in said plate 38, are capable ofsliding move ment to the right, as viewed in Fig. 5, against the tensionof the return springs 6|] when the upper ends of the sections 54 areengaged by the ends of short slots 5| appearing in a plate 4|] which isbeing selected by a shifting of its holder 4| to the right. However,where long slots 59 appear in the selected plate 46, the shiftingmovement of the latter will be relative to the pin sections 54 whichextend through said long slots, and no sliding movement of the latterpin sections will result. The lower section 55 of each device 53 ispivoted intermediate its ends to the press member 39, and when in itsnormal tilted position and with the press member lowered, the lower endof said section is disposed alongside its associated switch contact inthe banks 3|,32 as shown at the left of Fig. 5.

The selection of a control member 40 is ac complished after the pressmember 39 has been elevated to the position of Fig. 4, and thiselevation raises the pin sections 55 relative to their sections 54 byreason of the slot and pin connections 56, 51 therebetween, thuselevating the lower ends of the sections 55 to points above theirassociated contacts3l, 32. After the member 39 and sections 55 are thusraised and a control plate 40, for example the top one in Fig. 5, isselected by shifting the same and its holder 4| to the right as shown,wherever a short slot 5| appears in said plate with its left end engagedwith the upper end of the pin section 54 projecting through said slot,the shifting of said plate will slide said section 54 to the right inits slot 59 thus causing the associated pin section 55 to be rockedabout its pivot to a vertically aligned position with respect to itssection 54 and directly over the set of switch contacts individual tothe device 53 thus operated. The extent of shifting movement of theplate 40 and its holder 4| to the right is not sufficient to cause thelong slots 59 in said plate to slide the upper pin sections 54 whichextend therethrough, as will be seen at the left of Fig. 5. When thedevices 53 have been thus operated, the press member 39 moves downwardlyto carry with it all of the lower pin sections 55, and those which havebeen vertically aligned with their sections 54 are caused, by saiddownward movement, to engage with the upper contacts of theswitchcontacts in the banks 3 32 so that said contacts will be closedwhen the press member has reached its lowermost position. Thus,depending upon the number of short slots appearing in the selectedcontrol plate 40 and their placement therein, a like number of switchcontacts will be closed to energize the corresponding relays in thetransmission unit 2| to initiate the establishment, as will laterappear, of the particular instrument interconnection identified by theposition of the short slots 5| in said control plate.

The sequence of operation of the selector mechanism is such that thepress member 39 remains in its down position as long as a selection of acontrol member 40 is maintained and when another selection is initiated,the press member will begin its upward movement under the control of apress motor 6| to elevate the vertically aligned pin sections 55. Thosewhich have been vertically aligned by a previous operation and engagewith contacts 3|, 32 will, by reason of such elevation, permit suchclosed contacts to separate and thus open circuits for those relays inthe unit 2| which had been operated by the previous selection of acontrol element. However, as will be seen from the following descriptionof the circuits involving said relays, the opening of said closedcontacts does not release the interconnection of instruments previouslyestablished by the closure there of until the press member 39 is againlowered to close other contacts in the switch banks 3|, 32 to initiatethe establishment of a different interconnection. When said press memberhas reached the extent of its upward movement, as in Figs. 3 and 4, acam motor 62 is energized through a circuit established by the pressmotor. as will later appear, and said motor 62 then operates a series ofcams 63 to 68, one for each control plate 40, to successively shift theholders 4| and their control plates 40 until the desired one has beenselected whereupon the cam motor is stopped by the opening of itsenergizing circuit,

with the selected control plate in its shifted position wherein it hasoperated to set one or mo e of the transfer devices 53 in theiroperative positions preparatory to closing the associated contacts inthe banks 3|, 32. As soon as the cam motor 62 stops, it re-establishesan energizing circuit for the press motor which now resumes its rotationfrom the point where it was stopped until it has operated to restore thepress member 39 to its lower position. The selected switch contacts arenow closed and the corresponding relay or relays in the unit 2| areenergized to initiate the establishment of the instrumentinterconnection identified by the selected control plate 45.

The operation and stopping of the press motor 6| is accomplished througha switch pile 59 in a manner to be later described in detail, and saidmotor is mounted on the base 30 by a suitable support 10. Alongitudinally extending shai t H mounted in bearings 12 secured to theends of said base 39 is driven by the shaft 13 of said motor 6| throughworm gearing l4 and each end of said shaft ll carries a gear 15 meshingwith a similar gear 16 on a stub shaft 11 supported in the adjacentbearing 12. Each stub shaft 11 carries a cam 18 (see Figs. 2 and 8)having an internal groove 19 for receiving a roller on one end of alever 80 pivoted intermediate its ends on the adjacent frame 35 andhaving its other end connected to the press member 39 so that as thelever is rocked by an eccentric portion of the groove 19, said member 39will be raised and lowered as previously described. In Fig. 3, the partsare shown in the positions attained just prior to the press member 39reaching its uppermost position in which the motor 6| will be stoppedwhile a selection is being made of a control plate 49. Upon movement ofthe cam 18 (Fig. 3) a slight distance farther, an external cam 8|thereon will operate the switch pile 69 to open the circuit for themotor 6| at the contacts 82, as will appear more in detail in the courseof the description. The mo tor 6| then stops with said switch pile inreversed position and, after the proper control plate has been selected,said motor will again be energized to cause the cams 18 to rock thelevers 83 in a re verse direction so that the press member 39 will berestored to its lower position to accomplish the function of closing theproper switch contacts in the banks 3|, 32. As is well understood,clutch mechanisms (not shown) may be utilized to stop the earns 63 to68: andlllin: proper positionsnpon deenergization of. the respectivemotors 62. and GI.

When, in the sequence above. described, the press motor St is stoppedand the cam. motor 82 is energizedthelatter will, through its shaft 83,drive the worm gearing 84: connectedto the countershaft 85.:mountedinbearings 86on: the base3ll'. Operation of said shaft will rotate thevarious cams 63 to 68 thereon, and as said cams are turned they will, atcertainpoints in;their revolutions, operate the respective switch piles8.1 to 92 for purposeswhich will later appear. Each of. the cams 63'toEllis provided withan intemal groove 93 and the effective cam portionsof: all said grooves are circumferentially:displaced relative to eachother so that as the cams arerotated their respective grooves willsuccessively controlthe rocking movements of associated bell cranks 94pivoted. on a standard 95 on the base 30. The lower end of each bellcrank has a roller engaging in the groove 93 of its cam, andits upperend is connected. to the flange 44' of one of the holders 4| so that assaidcam is rotated. its bell crank 94willbe rocked toreciprocatesaidholder and the associated. control plate 40. The successivereciprocation of said holders continues until the one desired is in itsoperative or. shifted position, as shown at the top of Fig. 5. Uponreaching. such position,.the associated cam, for example the cam 68,will operate its switch pile 92 to openthe circuit for the cam motor6.2which will then stop with the selected holder and controlplate intheir right hand position wherein the transfer devices 53'actuated bythe short slots 5| in said plate will then be in position toclose theirrespective switch contacts when the press member is lowered. Stopping ofthe cammotor GZreenergizes the press motor 6| to lower the press member39 as previously mentioned. It is to be noted that as control plates aresuccessively reciprocated by their respective cams 63 to 88, certaintransfer devices 53 will momentarily assume operative positions underthe control of the short slots 5! in said plates, but as the unwantedplates are returned to normal by the complete reciprocation of theirholders, said operated devices 53 will also be restored by their springsBflandthus the lower pin sections 55 of said devices will resume theirtilted-positions.

Referring to Figs. 10 to 12, it will be seen that the switch wiper 96 ofthe substation selector 25 at the mainstation 21' is in position ,wherein its movable contacts are in engagement with the vertical bank ofterminals-individual to the substation which is designated in Figs. 1'and 10 as 25:; that the off key of the control element selector 28 (Fig.13) is depressed and the correspondin switch pile 8! is operated; andthat the contact wipers 91 and 98 (Fig. 12) of two multipositionmotor-driven switches 99 and I located at the switchboard H: are engagedwith terminals of said switches which are not connected, over theconductors lill. and H32 respectively, to the instruments l and I8. Thisis the condition causedby the depressionof the ofi" key of said selector23 that resulted in the selection of the control element 40 which, by.its selection, effected the disconnectionoi all saidinstruments l5, l8;and said condition continues until another element 40 is selected by thedepression of' one of the keys A toE and-said selection has resulted inthe closure of the contacts in banks 3|, 32 which are individual to thenewly selected'control element; The selector 28- is constructed-id anywelliknown', manner so that only one keyicanbe canbemade. Six of. thehorizontal rowseof. terminals in the substation selector 26. areidentified similarly to the keys of the selector 28 and are eachindividual to one of the control elements, and the other two horizontalrows of terminals insaid'selector ZGare joined to the line conductorsLl: and1L2 connectedto a suitable source of cur.- rent (not shown) for.operating the system.

It will. now be assumed, for purposes ofillustration, that it is desiredto establish an interconnection between certain instruments- IE; l8through the medium. of a control plate Mlwhich is individual to the keyA and to the toprow' of terminalssimilarly designated on the-selector26, and: that the signal. or impulse for. such inter-- connection is tobe transmitted from substation 251. After inserting the plug 29 into theoutlet at said substation but before depressing the key A, telephonic orother connection. is established between the substation and the operatorat the main station 2-! to ascertain which control: element. isthen ineifect, this being done under the assumption that a person other thanthe one who-selected the latter element is using a selector 28 differentfrom that. employed in establishing the previous connection. Having beeninformed rat the system is in the Oh position, the person at substation251 then requests that the operator at the main station connect theselector 26 to said substation, whereupon the switch wiper 96 is rotatedby saidoperator so that itscontacts will engage the vertical setof-terminals individual to said'substation, that is, the first setappearing at the left in the drawing. Key A-may now be depressed toinitiate the selection of the desired control plate iland, in doing so,any previously operated key in the particular selector 2'8 being used;will be restored.

Upon= operation of said'key A, a circuit is established for the pressmotor SI of the selector mechanism extending over the line conductor Lland through the motor, the now closed contacts 82, the conductor Icommon to the switch piles BT to 92 associated with the cam motor 62,the closed contacts I05 of the switch pil'e 92, the conductor H31, busliiil'of' the selector 26', the wiper I09 and terminal H0, thencethrough the plug and key contacts of the selector 28 connected tosubstation251, the conductor HI leading from I said substation, theterminal H2 of the selector 26, the-wiper H3 engaged thereby, bus 1 Handthen over the line conductor L2 connected to said bus. The motor 61' isenergized in this circuit and, in rotating the cams T8 in acounterclockwise direction, causes the press membcr 39 to be raised'fromits lowered position with the results previously described. Asthe cam18' (Fig. 3) reaches the position shown, its external cam 8| engageswith the arm of the switch pile 69 and a slight additional movementcauses a reversal of the contacts of said pile to open' the energizingcircuit for said motor at the contacts-82' and the motor then comes torest. As said contacts 82 are opened; the contacts H Sofsaid'pile areclosed; thereby establishing an energizing circuit for the cam motorSTextending-ov-er the lineconduct'or LI and conductor IIB, through saidmotor 62, the closed contacts II5, the conductor I05, and from thenceover the previously described circuit through the closed contacts I06,the selectors 2B and 29 and back to the line conductor L2. The motor 62now drives the shaft 85 to rotate the series of cams '63 to 68 tosuccessively reciprocate the holders 4| and their control plates 40until the cam 68 individual to the desired control plate is actuated toreverse the contacts of the switch pile 92, thereby breaking theenergizing circuit for the cam motor at the contacts I06 and thusstopping the motor with the selected control plate and its holdershifted to their operative position as shown in Fig. 5. During therotation of the shaft 85 the cam 63 first permits restoration of theswitch pile 81 which was reversed by a previous operation, and the othercams 64 to 61 then momentarily and successively reverse their respectiveswitch piles 88 to 9| but this latter action has no effect upon thecircuit since the terminals of the selector 26 joined to the latterswitch piles are not connected to the substation which is now in use.Reversal of the switch pile 92 reestablishes an energizing circuit forthe press motor 6| extendin over the line conductor LI and through themotor to the now closed contacts II! of the switch pile 69, theconductor II8, the closed contacts N9 of the switch pile 92, and fromthence over the previously described circuit including the conductor I01back to the line conductor L2. The motor 6| now operates until cam 8| onthe cam 18 (Fig. 3) disengages from the arm of the switch pile 59 topermit it to restore and, in so operating, the two cams I restore thepress member 39 to its lowered position to close the switch contacts inthe banks 3|, 32 which have been selected by the selection of thecontrol plate 40. Thereupon, said cams and the motor 6| come to rest.Restoration of the switch pile 69 closes the contacts I04 thereof toestablish a signaling circuit to identify, at the main station 21, thecontrol plate 40 now in use. This circuit extends over the lineconductor LI through the contacts I04, the conductor I20, the closedcontacts I2| on the switch pile 92, the lamp or other signal I22 andfrom thence over the conductor I23 to the line conductor L2. The signalI22 remains energized in this circuit until the switch pile 92 isrestored by a subsequent operation.

In Figs. 11 and 12 there are shown, respectively, the circuits for onecomplete set of relays in the transmission unit 2|, and twomulti-position switches 99 and I08 each of which is controlled by oneset of said relays. As shown, the complete set of relays in Fig. 11 isconnected to the switch H10, while the set serving the switch 99 isindicated at I24 and is a duplicate of the illustrated complete set.Also, at I25 there is shown a third group of conductors which wouldconnect with a third set of similar relays if such were required toextend the system. Each of the switches 99, I00

comprises in addition to the actual switch sec.

tions thereon, two control sections I26, I21 containing eight sets ofterminals AI to HI and A2 to H2, respectively, and each pair ofterminals AI, A2, etc. has associated therewith one of the relays A3 toH3. Further, as shown in Fig. 11, there are two banks of switch contacts3|, 32, also illustrated in Fig. 9, and said banks comprise, in all,twenty-four sets of contacts arranged in three groups of eight each, anddesignated as A4 to H4, A to H5, and A5 to H6, the first group beingconnected to the illustrated eight relays A3 to H3, the second group tothe corresponding relays at I24 which control the switch 99, and thethird group to a similar set of relays which may be connected to theconductors I25 for the control of still another multi-position switchindicated at I28 (Fig. 11) by the characters Al to HI and A2 to H2.

The circuits are illustrated in the on position which is assumed to havebeen previously effected, and it will now be further presumed that, inorder to secure this position, a control element 40 was selected Whichresulted in the closure of the switch contacts H4 and H5, with theconsequent operation of the relay H3 and the corresponding relay in thegroup I24. The operation of these two relays controlled the switches 99,I00, as previously mentioned, to set their wipers 9T, 98 on the rows ofterminals I29, I30, associated with the control terminals HI and H2 inboth switches, thereby effecting the disconnection of all in strumentsI6 and I8 since said terminals I29, I30 are not connected to theconductors IBI, I92 and the latter are, therefore, not joined to theinterconnecting buses I3| to which extend leads from the wipers 9T, 98.

With the above condition existing, the line conductor LI is connected,through the closed contact H4 and intermediate winding I32 of theauto-transformer I33 for the motor of relay H3, to the line conductor L2in which is included the current limiting reactor I34; and saidconductor LI is also connected through the closed contact I35 of saidrelay and the other intermediate winding I36 of said transformer, to theline L2. Therefore, said conductor LI being connected to equal andopposite voltages in the two windings I32, I36, the relay will remain inits operated position with its entire switch pile closed until theswitch contact H4 is opened by the elevation of the engaged pin section55 when the press member 39 is raised upon initiation of the selection.of another control element 40, as previously described. When saidswitch contact H4 is opened, the conductors LI and L2 will be connectedin a circuit extending only through the transformer winding I35 andincluding the closed relay contact I35, thus inducing a voltage acrossall the windings of the auto-transformer to again energize the motor ofrelay H3 which continues to operate until the contacts of the relayswitch pile are opened, whereupon said motor comes to rest. The sameoperation occurs in the corresponding relay in group I24 when the switchcontact H5 is opened. The opening of contacts H4, H5 do not, aspreviously mentioned, disturb the positions of the switches 99, I sincethe conductors I31, I38 leading from the control terminals HI, H2 of therespective switches are not connected to any of the contacts of theswitch piles of said relays. Hence, any condition existing betweeninstruments I6, I9 will continue until the selection of another controlelement 40 has been completed and the proper switch contacts in thebanks 3|, 32 have been closed.

It will now be assumed that the selector mechanism of Figs. 2 to 9 hasbeen operated to select a control element 40, such as the one at the topof Fig. 5, having two short slots 5| therein which will operate theswitch contacts G4 and A5 in the banks 3|, 32. The closure of thesecontacts will result in the interconnection of instrument Ito with allthree instruments 8a, lab and I80, as will now be described.

Upon closure of the switch contact G4, the relay G3 will be energizedover a circuit extending from conductor Ll through said contact, thewinding I39 of the auto-transformer I33 associmon buses I3 I.

1 1'4 ated with said relay, the motorthereof, and'back through thetransformer windings I40 and I36 to the conductor L2. Said motor nowoperates until the contact I35 closes, whereupon conductor LI isconnected to both transformer windings I32 and I36, as previouslydescribed in connection with the relay H3, and the motor will stop withall contacts of the relay switch pile closed. It will be noted that, inaddition to the contact I35, each relay G3, etc. is provided with twoother groups I40, I4| of seven contacts each, with the groups I40 and MIconnected, respectively, to leads X and Y of the three-phase source ofsupply indicated at I42 and to various conductors of the common groupsI43 and I44, with the exception of the conductors I45 and I46 therein.These latter conductors are connected to the control terminals GI and G2of the switch I and said terminals are therefore not energized. However,all of the seven remaining terminals .Al, A2, etc. of said switch areenergized by closure of the-contact groups I46, MI and their connectionto the leads X and Y, and with the switch wipers I41 now on theterminals HI, H2, the motor I48 of the switch will be energized over theleads X, Y and the common lead Z to move said switch wipers until theyengage the non-energized terminals GI and G2, whereupon the motor willstop. The movement of the wipers I41 is transmitted to the wipers 98 andthe latter will consequently come to rest on the row of terminals I49associated with said terminals GI, G2. All six of the terminals I49 areshown connected to the conductors I02 leading to the instruments I841,I81) and I80 and therefore the latter will be joined, through the wipers98, to the com- By following the preceding description with respect tothe group of relays I24, it will be seen that when the switch contact Ain the bank 32 is closed by the selection of the desired control element40, the corresponding relay A3 of said group I24 will be energized tooperate the switch 99 so that its wipers I-50 will stop on the controlterminals Al, A2 and the wipers 97 will engage the associated row ofterminals I5I, with the result that the instrument Ifia will beconnected, over conductors I! and through said wipers 91, to the commonbuses I BI, and therefore interconnected to all three instruments IBa,I81) and I80 which have been joined to said buses by the operation ofswitch I90. In the same manner, it will now be apparent that othercombinations of instruments may be interconnected by the selection ofthe required control plates now in the magazine of theselectormechanism, and that by removing said plates and substituting others,still more combinations of interconnections may be accomplished. It alsowill be possible, by the addition of more sets of relays in the unit 21and more switches in the switchboard I5 and by increasing the number ofshort slots 5| and contacts in the banks 3|, 32, to materially increasethe number of combinations obtainable.

I claim:

1. In a switching system for selectively interconnecting a plurality ofinstrumentalities, the combination of signaling means, a plurality ofnormally open switch contacts, a selector mechanism controlled by saidsignaling means to selectively operate said switch contacts in variouscombinations thereof, a like plurality of relay means each operable byone of said operated switch contacts, and a plurality of electrically 12operated switches positionable by said relay means to interconnectsaidinstrumentalities in accordance with the selected operation of saidswitch-contacts.

2. In a switching system for selectively interconnecting a plurality ofinstrumentalities, the

combination of a plurality of signaling stations, a plurality ofnormally open switch contacts, a selector mechanism, signalingmeans'operable from one of said plurality of signaling stations, amanually settable switch "for interconnecting said selector mechanismand any one of said stations, said selector mechanism being controlledby said signaling means to selectively operate said-switch contacts invarious combinations thereof, a plurality-of relays each individual toand operable by one of said switch-contacts, and:a pluralityofelectrically operated switches :positi-onable 'by' said relays tointerconnect said instrumentalities :in accordance with the :selectedoperation of said switch contacts.

3. In a switching system for selectively interconnecting a plurality ofinstrumentalities, the combinationof-a plurality-of signaling stations,a plurality of normally-open-switch contacts,,a selectormechanism,signaling means operablefrom one of said plurality'of-signaling-stations, a manually settable switch for interconnectingsaid selector-mechanism and said signaling station, said selectormechanism being controlled by said signaling means to selectivelyoperate said switch contacts in various combinations thereof, aplurality of rotary relays each individual to and operable by one ofsaid switch contacts, and a plurality of electrically operated rotaryswitches positionable by said relay means 'to interconnect saidinstrumentalities in accordance with the se lected' operation ofsaidswitch contacts.

4. In a switching system for selectively interconnecting variouscombinations of a plurality of instrumentalities, the combination'with aselector mechanism wherein a plurality of control elements eachindividual tonne of said combinations is selectedto identify the same;of asignal transmitting means for activating said selector mechanism .toselect one of said control elements, switching contacts controlled bysaid selector mechanism following the selection of said control element,relay means operated by said switching contacts, and switching meanspositionable by said relay means to interconnect said instrumentalitiesin accordance with the selected control element.

DONALD L. HERR.

REFERENCES CIT-ED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

